1. Field of Invention
The present invention relates to electro-optical devices and electronic apparatuses. More specifically, the invention relates to an electro-optical device including an organic electroluminescent material and to an electronic apparatus including the electro-optical device.
2. Description of Related Art
The related art includes color electro-optical devices in which light-emitting elements made of light emitting material, such as organic fluorescent material, are sandwiched between pixel electrodes (anodes) and cathodes, in particular an organic electroluminescence (organic EL) display device employing organic EL material as the light emitting material. A related art electro-optical device (the organic EL display element) is summarized below.
FIG. 13 is a schematic illustrating the wiring structure of the related art electro-optical device. As shown in FIG. 13, a plurality of scanning lines 901, a plurality of signal lines 902 extending in the direction of intersecting the scanning lines 901 and a plurality of light-emitting power source wiring lines 903 extending in parallel to the signal lines 902 are arranged in the related art electro-optical device, and a pixel region A is provided at each intersection of the scanning lines 901 and the signal lines 902. Each of the signal lines 902 is connected to a data line driving circuit 904 comprising shift registers, level shifters, video lines and analog switches. Each of the scanning lines 901 is connected to a scanning line driving circuit 905 comprising shift registers and level shifters.
Further, each of the pixel regions A is provided with a switching thin film transistor 913 a gate electrode of which is supplied through the scanning line 901 with scanning signals, a holding capacitor Cap to hold image signals supplied through the switching thin film transistor 913 from the signal line 902, a current thin film transistor 914 a gate electrode of which is supplied with image signal held by the holding capacitor Cap, a pixel electrode 911 into which driving current flow from light-emitting power source wiring lines 903 when being electrically connected to the light-emitting power source wiring lines 903 through the current thin film transistor 914, and a light-emitting layer 910 sandwiched between the pixel electrode 911 and a cathode 912. The cathode 912 is connected to a power source circuit 931 for cathode.
The aforementioned light-emitting layer 910 includes three types of light-emitting elements; a light-emitting layer 910R emitting a red light, a light-emitting layer 910G emitting a green light and a light-emitting layer 910B emitting a blue light. The respective light-emitting layers 910R, 910G, 910B are arranged in striped shapes. Further, each of the light-emitting power source wiring lines 903R, 903G, 903B connected respectively to the light-emitting layers 910R, 910G, 910B through the current thin film transistors 914 is connected to a light-emitting power source circuit 932. The light-emitting power source wiring lines are arranged for every color, because the driving potentials of the light-emitting layers 910 are different for every color.
In the above constitution, when scanning signals are supplied to the scanning lines 901 to turn on the switching thin film transistors 913, the electric charge corresponding to image signals supplied to the signal lines 902 at that time is held in the holding capacitors Cap. The ON/OFF state of the current thin film transistors 914 is determined in accordance with the quantity of electric charge held in the holding capacitors Cap. In addition, current flow through the current thin film transistors 914 from the light-emitting power source wiring lines 903R, 903G, 903B to the pixel electrodes 911, and driving current flow through the light-emitting layer 910 to the cathode 912. At that time, the quantity of emitted light corresponding to that of current flowing through the light-emitting layer 910 is obtained.